1. Field of the Invention
The present invention relates to embroidery stitching device and sewing machine having a free arm and more particularly relates to the embroidery stitching device and sewing machine having a free arm which is provided to embroider a cylindrical work thereon and has sensor means for detecting a condition that a part of the work contacts the free arm during stitching operation to prevent the work from being further stitched and then for determining and/or indicating an area where the work may be embroidered.
2. Prior Art
It is generally known that a sewing machine or device for embroidery stitching is provided with a free arm which is used in case embroidery patterns are stitched at a work of cylindrical shape such as a sleeve of clothes. In case an embroidery stitching operation is carried out at the cylindrical work which is held by an embroidering frame and placed on the free arm as surrounding the same, it is required to move the embroidering frame in an area where the embroidering frame is allowed to move without the work being caught by the free arm. If the stitching operation is continued beyond the area, the mechanism and/or the work may be damaged.
As to the embroidery stitching device and sewing machine having a free arm, the area where the embroidering frame may be moved is generally predetermined at the time of production of the device and/or sewing machine having a specific design while the area where the free arm may allow the work to move is different in dependence upon the individual works to be embroidered.
The machine user is, therefore, required to calculate the size of the work to be embroidered so as to decide if the work may be embroidered in the predetermined area. It is actually a very troublesome task for the machine user to make the decision. The decision, if not correct, will cause a damage of the work and/or the mechanism.
The invention has been provided to eliminate the defects and disadvantages of the prior art.
It is, therefore, a primary object of the invention to provide embroidery stitching device and sewing machine having a free arm having sensor means provided therewith to detect if the work is in contact with the free arm during stitching operation and to decide and/or indicate an area where the work may be stitched.
It is another object of the invention to provide the stitching area deciding and/or indicating device which is simple in structure and reliable in operation.
The other objects and advantages of the invention will be apparent in the following detailed description of the invention in reference to preferred embodiments.
For attaining the objects, the embroidery stitching device having a free arm of the invention comprises means for holding a work to be embroidered and for moving the work, means provided on the free arm to detect a contact or access between said work and said free arm.
The detecting means may detect a contact or access between said work and said free arm to stop the embroidery stitching device or to indicate the machine user to take a required action.
The embroidery stitching device may include means which is responsive to a detecting signal from the detecting means to detect an area where the work may be moved and indicate the machine user to decide if the stitching operation may be continued or not.
The embroidery stitching device may further include means for giving information regarding a pattern to be embroidered to the work and means responsive to the information from the information giving means and the information from the detecting means to discriminate if the pattern may be embroidered in the detected area.
In this case, it is preferable that embroidery stitching device further includes means for designating a position where the pattern is embroidered, the position designating means being operated to change an embroidering position in case the discriminating means discriminates that the pattern will not be embroidered in the detected area.
It is further preferable that the embroidery stitching device includes means for designating a size of a pattern to be embroidered and means for changing the designated size of the pattern in case the size of the pattern designated by the designating means is discriminated by the discriminating means to be something to be improper for embroidering.
The embroidery stitching device as above mentioned will be made up in a swing machine for embroidery stitching operation.